Class 7 Radioactive Materials: A Shipping Classification Guide

Most dangerous goods classifications are based on what a substance does chemically: it burns, corrodes, or releases toxic vapors. Class 7 works differently. It is the only hazard class defined by a measurable physical property: the emission of ionizing radiation. That distinction shapes every decision you make before a radioactive shipment moves.

For life sciences and nuclear medicine teams shipping radiopharmaceuticals, research isotopes, or diagnostic tracers, understanding Class 7 classification is not optional. It determines your UN number, your packaging tier, your label category, and which carriers can legally accept your shipment.

What Makes a Material Class 7

A material falls under Class 7 when it contains radionuclides above specific activity thresholds defined in the IATA Dangerous Goods Regulations (DGR) and the U.S. Department of Transportation (DOT) Hazardous Materials Regulations (49 CFR Part 173). The relevant thresholds are expressed as activity concentrations (becquerels per gram) or total activity (becquerels).

Materials below these thresholds are considered exempt from Class 7 requirements and may ship without radioactive labeling or a Shipper's Declaration. Most natural materials with trace radioactivity, such as certain mineral samples or food products, fall into the exempt category.

Radiopharmaceuticals used in diagnostic imaging and targeted radiotherapy always exceed exempt thresholds and require full Class 7 treatment. For a complete walkthrough of what happens after classification, including packaging selection, documentation, and final-mile handoff requirements, see our radiopharmaceutical shipping compliance guide.

The Four UN Numbers Life Sciences Shippers Use Most

Class 7 encompasses dozens of UN numbers organized by package type and activity level. Four appear most frequently in pharmaceutical and research shipping.

UN2908: Radioactive Material, Excepted Package, Empty Packaging. This applies to previously used radioactive packaging that contains only residual contamination within defined limits. It carries the least regulatory burden of any Class 7 designation.

UN2910: Radioactive Material, Excepted Package, Limited Quantity of Material. This covers low-activity materials where total activity falls below IATA Table 2-13 limits. Many research isotopes shipped in small quantities qualify here. Documentation requirements are significantly lighter than for other Class 7 entries.

UN2911: Radioactive Material, Excepted Package, Instruments or Articles. This applies to devices containing radioactive components, such as certain analytical instruments or calibration sources, where the radioactive material is fully enclosed within equipment.

UN3332: Radioactive Material, Type A Package, Special Form. This is the standard UN number for most clinical radiopharmaceuticals shipped in sealed source form, including many targeted radiotherapy agents. It requires a full Type A package and a complete Shipper's Declaration for Dangerous Goods.

The proper shipping name paired with each UN number must appear exactly as written in the IATA DGR on all shipping documents and the air waybill. Abbreviations or informal names are not acceptable. Mercury's pharmaceutical shipping team supports classification decisions for both clinical and research-stage radioactive materials.

How to Calculate the Transport Index

The transport index is a number that represents the radiation dose rate at one meter from the external surface of the package, measured in millisieverts per hour (mSv/h) and then multiplied by 100. If a measurement of 0.03 mSv/h is recorded at one meter, the TI is 3.

A TI of zero means the measured dose rate at one meter is 0.005 mSv/h or less. This is not the same as no radioactivity. It means the external radiation level is low enough that regulatory authorities have assigned it a TI of zero for classification purposes.

For fissile materials, the TI calculation method differs and incorporates criticality safety factors. Most radiopharmaceuticals are not fissile, so the standard dose-rate method applies.

You must perform this measurement on the actual packaged shipment, not on the unshielded source. The shield, container geometry, and packing materials all affect the external dose rate.

Radioactive Label Categories Assigned by TI

Once you have calculated the TI and measured the surface dose rate, you assign one of three radioactive label categories. This label must appear on at least two opposite sides of the outer package.

White-I applies when the surface dose rate does not exceed 0.005 mSv/h and the TI is zero. These packages present the lowest external radiation exposure and face the fewest carrier restrictions. They may travel on passenger aircraft alongside other cargo without segregation requirements.

Yellow-II applies when the surface dose rate does not exceed 0.5 mSv/h, and the TI falls between 0 and 1. These packages require physical segregation from passengers, crew, and undeveloped photographic film on aircraft. Many diagnostic radiopharmaceuticals shipped in standard lead pots fall into this category.

Yellow-III applies when the surface dose rate does not exceed 2 mSv/h and the TI falls between 1 and 10. These shipments must travel on cargo aircraft only and require advance coordination with the airline's dangerous goods acceptance team. The Cargo Aircraft Only (CAO) notation must appear on all documentation.

Any package exceeding a surface dose rate of 2 mSv/h or a TI above 10 requires exclusive use transport, meaning it occupies a dedicated vehicle or aircraft compartment with no other cargo.

Proper Shipping Name and Activity Declaration

Beyond the UN number and TI, every Class 7 shipment declaration must state the radionuclide identity and the total activity at the time of shipment in becquerels (Bq) or curies (Ci). For radiopharmaceuticals with short half-lives, this activity value is time-stamped to a specific reference time, typically the end of synthesis or calibration time.

The receiving facility needs this value to calculate the activity expected at the time of administration. Misreported activity figures at the declaration stage cascade into dosing errors at the clinical end.

For shipments containing multiple radionuclides, each must be listed separately with its individual activity. Mercury's clinical trials logistics team handles multi-radionuclide shipment declarations for oncology and research programs across the U.S. and internationally.

How Class 7 Differs From Other Dangerous Goods Classes

Shippers experienced with biological substances (Class 6.2) or flammable materials sometimes assume that Class 7 follows a similar framework. It does not. Three differences stand out.

First, the regulatory authority is different. Class 6.2 biological shipments are governed primarily by IATA and DOT. Class 7 adds the Nuclear Regulatory Commission (NRC) as a parallel regulator with its own licensing, reporting, and transportation requirements. An NRC or Agreement State license is required to possess and transfer most radiopharmaceuticals. For a side-by-side comparison of how biological substance classification works, see our guide to classifying biological shipments.

Second, the packaging certification process is different. Class 6.2 packaging relies on validated systems tested for leak resistance and pressure. Class 7 Type A and Type B packages must pass a defined set of performance tests specified in IAEA Safety Series No. SSR-6, including drop tests, stacking tests, water immersion, and for some package types, thermal and puncture tests. Package designs must be certified before use.

Third, carrier qualification is different. Any carrier approved for general dangerous goods can accept Class 6.2 shipments. Class 7 requires specific carrier authorization for radioactive materials, and Yellow-III shipments require airline acceptance of the specific consignment before the shipment is tendered. For a broader overview of how dangerous goods classes are structured, see Mercury's hazardous materials guide.

How Mercury Supports Class 7 Classification

Correct Class 7 classification requires accurate activity measurements, knowledge of current IATA DGR thresholds, and familiarity with NRC licensing requirements. A single error in UN number selection or TI calculation delays the shipment and may trigger regulatory review.

Mercury's team supports life sciences and nuclear medicine organizations with Class 7 documentation preparation, carrier coordination for radioactive materials, and compliance review before each shipment tenders. Our pharmaceutical and biotechnology shipping services provide the infrastructure and expertise that Class 7 shipments demand.

Contact Mercury today to discuss your radioactive material shipping requirements and build a compliant classification process from the ground up.